• 제목/요약/키워드: Analytical precision

검색결과 818건 처리시간 0.023초

볼스크류 너트부의 강성 모델링과 불확도 해석 (Modeling and Uncertainty Analysis of Ballscrew Nut Stiffness)

  • 민복기;조뢰;김경호;박천홍;정성종
    • 한국정밀공학회지
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    • 제32권5호
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    • pp.415-422
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    • 2015
  • Ballscrews are important motion transfer and positioning units of industrial machinery and precision machines. Positioning accuracy of the feed drive system depends upon axial stiffness of ballscrew systems. As the nut stiffness depends upon preload and operating conditions, analytical modeling of the stiffness is performed through the contact and body deformation analysis. For accurate contact analysis, the contact angle variation between balls and grooves is incorporated in the developed model. To verify the developed mathematical stiffness model, experiments are conducted on the test-rig. Through the uncertainty analysis according to GUM (Guide to the expression of Uncertainty in Measurement), it is confirmed that the formulated stiffness model has over 85% estimation accuracy. After constructing the ballscrew DB, a quick turnaround system for the nut stiffness estimation has been developed in this research.

홀로그래픽 산섭법을 이용한 미소변형 측정법 (The Measurement Method of Small Deformation by using Holographic Interferometry)

  • 강영준;문상준;최장섭
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1993년도 추계학술대회 논문집
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    • pp.273-278
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    • 1993
  • Conventional measurement methods for non-destructive testing(NDT) in nuclear power plants other industrial plants have been performed as the methods of contact with objects to be inspect, but those methods have been taken relatively much time to be inspected. Holographic interferometry which is a non-contact optical measurement method using a coherent light can overcome these demerit, and also has an advantage that the quantitative measurement of small deformation for large areas can be accomplished at a time with high precision. In this paper the comparisons of the experimental results from holographic interferometry with those form the finite element method(FEM) and the analytical solutions of elastic equation are discussed.

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표면실장기 기저부의 동특성 연구 (A Study of Dynamic Characteristics for Frame Base of the Chip Mounter)

  • 성기창;박진무
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2002년도 춘계학술대회 논문집
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    • pp.807-811
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    • 2002
  • As the requirements on precision and speed of motion in chip mounter increase, vibration forces are always exerted on operating conditions. To insure safety of the chip mounter, the vibration must be kept within an acceptable limit. The focus of this paper is on the identification of dynamic load characteristics and the estimation of static and dynamic stiffness characteristics for Frame Base by judicious selection of the number and the location of the support points. This study carried an analytical and experimental method to estimate the dynamic characteristics in structure.

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스피닝 공정을 이용한 다단 원형 컵 형상의 성형성에 관한 연구 (The Spinnability of Multi-step Cylindrical Cup in Spinning Process)

  • 박중언;한창수;최석우;김승수;나경환
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2001년도 춘계학술대회 논문집
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    • pp.1016-1020
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    • 2001
  • The spinning is a very effective manufacturing technology for short production runs in a variety of sizes and shapes, because it can form the cross-section or tubular parts various shapes. However extensive experimental and analytical research has not been carried out. In this study, and fundamental experiment was conducted to improve productivity with process parameter such as tool path, angle of roller holder(a), feed rate(v) and corner radius of forming roller(Rr). These factors were selected as variables in the experiment because they were most likely expected to have and effect on spring back. The clearance was controlled in order to achieve the precision product which is comparable to deep drawing one. And also thickness and diameter distribution of a multistage cup obtained by shear spinning process were observed and compared with those of a commercial product produced by conventional deep drawing.

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Ruled Surface의 곡률이론을 이용한 새로운 로봇궤적제어기법

  • 김재희;김상철;유범상
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1997년도 춘계학술대회 논문집
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    • pp.683-691
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    • 1997
  • This paper presents a new robot trajectory generation method based on the curvatre theory of ruled surfacees. robot trajectory is represented as a ruled surface generated by the TCP (Tool center point ) and any one unit vector among the tool frame (usually denoted O, A,N). The curvature theory of ruled surfaces provides the robot control algorithm with the motion property oarameters. The proposed method eliminates the necessity of approximation technic of either joint or cartesian interpolation. This technic may give new methodology of precision robot control. Especially this is very efficient when the robot traces an analytical or form surface if the surface is geometrically modelled.

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동조 자이로스코프 서스펜션의 굽힘자 해석 및 시험 (Analysis of flexure stiffness and stiffness test in DTG)

  • Youn, J.O.;Kim, J.H.;Lee, J.G.
    • 한국정밀공학회지
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    • 제13권5호
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    • pp.30-37
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    • 1996
  • The objective of this research is to explore the analysis and test method for the reliable design and fabrication of a high precision dynamically tuned gyroscope. The tuning frequency is decided by the calculation of mass moment of inertia of rotor and gimbal and the stiffness of flexures. Due to the complex geometry of the flexure, calculation of the stiffness of the suspension flexure is difficult. In this paper, three analytical methods for obtaining the stiffness of the flexure are porposed and a special testing method is used for checking the accuracy of the computed results.

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고속정밀 서보제어를 위한 직구동 다관절 메니플레이터의 시간제어기 설계 (Time Delay Controller Design for the High Speed Precision Servo-Control of the Direct Drive Multi-axis Manipulator)

  • 이태경;김학성;정상철;최용제;안태영
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1996년도 추계학술대회 논문집
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    • pp.1004-1011
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    • 1996
  • This paper covers the technology developmental stage work for the automatic ammunition loading system mainly focusing on the controller design of the electro-hydranlic type direct drive multi-axis manipulator. Mathematical model of the plant derived and PIDM servo-controller structured. Comparative study between the analytical and experimental work has been carried out to help understand the response property of the direct dine multi-axis robot. In the direct drive robot, non-negligible amount of disturbance and load Induced dynamics variation are transmitted to the drive axis and nonlinearity is highly observed. Thereupon a robust controller Implementing time-delay control law is proposed, and computer simulation confirms the possibility for the time-delay control application against the unpredictable disturbance and load-Induced dynamics variation.

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구형 인볼류트 베벨기어쌍의 각속도비에 관한 해석적 연구 (An Analytical Investigation on the Ratio of Angular Velocity in Spherical Involute Bevel Gearsets)

  • Park, N.G.
    • 한국정밀공학회지
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    • 제12권5호
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    • pp.40-45
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    • 1995
  • The kinematical relationship of bevel gearsets lies at the root of the gear design. As the demand on precision bevel gears is increased in the related industries, the kinematic analysis of a pair of sperical involute bevel gears needs to be exactly evaluated for the computer aided design. Pitch cone angles of bevel gearsets have been calculated under the assumption that the geared system is equivalent to a coned roller system without slipping. But this kinematical model involves some errors in the value of the ratio of angular velocity. In this paper, the ratio of the angular velocity is exactly derived, based on the perfect involute tooth surface. Four nonlinear equations representing the kinematical relationships are numerically solved to obtain the pitch and base cone angles. The ratios of angular volocities according to pressure and shaft angles are calculated and compared with those of the approximate gear model.

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홀로그래픽 간섭법을 이용한 미소변형 측정법 (The Measurment Method of Small Deformation by using Holographic Interferometry)

  • 강영준;문상준
    • 한국정밀공학회지
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    • 제12권9호
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    • pp.52-58
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    • 1995
  • Conventional measurement methods for non-destructive testing(NDT) in nuclear power plants and other industrial plants have been performed as the methods of contact with objects to be inspect, but those methods have been taken relatively much time to be inspected. Holographic interferometry which is a non-contact optical measurement method using a coherent light can overcome these demerit, and also has an advantage that the quantitative measurement of small deformation for large areas can be accomplished at a time with high precision. In this paper the comparisons of the experimental results form holographic interferometry with those from the finite element method(FEM) and the analytical solutions of the elastic equation are discussed.

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비교숙련도 시험을 통한 도시대기분진에 대한 중성자방사화분석법의 품질관리 (Quality Control on Neutron Activation Analysis for Urban Dust by the Proficiency Test)

  • 문종화;김선하;정용삼
    • 분석과학
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    • 제15권5호
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    • pp.433-438
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    • 2002
  • 국제원자력기구로부터 제공받은 2종 (V-50, P-50)의 인공적으로 준비된 여과지상의 도시분진시료중의 미량원소를 중성자방사화분석법을 사용하여 비파괴 분석하였다. 중성자방사화분석의 품질관리를 위해 미국표준기술원의 인증표준물질 (Urban Particulate Matter, NIST SRM1648)이 사용되었으며 여과지상의 분진시료에서는 약 20종의 원소를 분석하였다. 측정결과는 실험실간 비교 및 숙련도 평가를 위하여 중성자방사화분석법, 하전입자유도 X-선 방출분광법, 유도결합플라즈마 질량분석법 등을 이용한 세계 40개국, 49개 실험실의 분석값들과 함께 통계처리 되었다. 통계 처리한 결과, 본 실험실의 분석값들의 Z-score가 ${\pm}2$ 이내에 들어오는 결과를 얻었으며, 숙련도 시험도 분석된 모든 원소의 정확도와 정밀도가 기준에 통과되는 신뢰성 있는 결과를 얻어 현재 수행하고 있는 대기분진시료들의 분석품질관리가 적합함을 입증하였다.